Feature/add standard import tool

[a-solovyev12]

Description

This PR adds a standard tool for importing expression data and pre-trained classifiers for SCXA datasets.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• I have made any required changes to upstream dependencies for a tool wrapper, and they are available in distribution channels (e.g. Pip, Conda).
• If I have updated the underlying software for a tool wrapper (e.g. scanpy-scripts by changing the value of @TOOL_VERSION@), then I have reset all 'build' values to 0 (e.g. @TOOL_VERSION@+galaxy0)
• If I have updated a tool wrapper without a software change, then I have bumped the associated 'build' values (e.g. @TOOL_VERSION@+galaxy0 @TOOL_VERSION@+galaxy1)